Showing papers by "Harry A. Quigley published in 1981"

Optic nerve damage in human glaucoma. II. The site of injury and susceptibility to damage.

Abstract: • We examined the histologic structure of the optic nerve head in 15 eyes of nine persons with a known glaucoma history. All had been seeing eyes, varying from normal visual acuity and visual field to advanced glaucoma damage. The site of damage to nerve fibers is the scleral lamina cribrosa, where there is local blockage of axonal transport. Early cup size increase prior to definite field loss results from loss of nerve fibers, not from damage to astrocytic glial cells of the nerve head. No selective damage to nerve head capillaries is seen in mildly damaged specimens. Scanning electron microscopic analysis suggests that the structure of the lamina cribrosa is an important determinant of the degree of susceptibility to damage by elevated intraocular pressure.

Regional Differences in the Structure of the Lamina Cribrosa and Their Relation to Glaucomatous Optic Nerve Damage

Abstract: • Previously, there was no feature of optic nerve head anatomy or physiology that could explain the greater susceptibility for early damage in some nerve fibers by chronic glaucoma. Using a new technique for scanning electron microscopic examination of human optic nerve heads, regional differences were found in the fine structure of the lamina cribrosa. The superior and inferior parts of the lamina at the level of the sclera appear to contain larger pores and thinner connective tissue support for the passage of nerve-fiber bundles than the nasal and temporal parts of the lamina. Since the superior and inferior laminar zones are the sites of passage for arcuate area ganglion cell axons that are most susceptible to glaucoma damage, the differences found in laminar structure in these locations may explain the characteristic pattern of early glaucomatous field loss.